Field of the Disclosure
The disclosure relates to an optical touch system, a method of touch detection, and a computer program product.
Description of Related Art
Recently, touch electronic products have become very popular among consumers due to the easy operation and high intuition thereof, and have gradually become mainstream in the market. Among the resistive, capacitive, and rear projection touch screens used in the past, the capacitive touch screen has the best touch effect; however, the capacitive touch screen is also the most expensive, and the cost thereof increases with larger screen size, thereby limiting the application of the capacitive touch screen.
To find an alternative to the capacitive touch screen, an optical touch screen using an optical lens to detect a touch location is currently available. The optical touch screen has the advantages of low cost and good accuracy, and is more advantageous in the competitive market. As a result, the optical touch screen has currently also become an alternative for a large-size touch screen.
Another optical touch screen uses a plurality of optical lenses or a reflective frame at the border of the screen to capture an image of the operation of a user's finger on the screen, and to analyze the location of a shadow in the captured image generated due to the finger blocking light. As a result, the exact location of the touch point can be determined. In particular, the cost of disposing a reflective frame is far less than the cost of disposing a plurality of optical lenses. Therefore, the optical touch screen using a reflective frame has a price advantage. Generally, when detecting two touch points, a set of true touch points and a set of false touch points are generated. If two touch points approach a touch region at different time points, then the true touch points can be determined without additional hardware. However, determining which set contains the true touch points when two touch points approach the touch region at the same time is a current issue that needs to be solved in the development of an optical touch system.